2 2 2-trifluoroethyl trifluoromethanesulfonate cas no July 8, 2019 16 32 64 128 2 2 2-trifluoroethyl trifluoromethanesulfonate 2 2 2-trifluoroethyl formate 2 2 2-trifluoroethyl acetate 2 2 2-trifluoroethanol 2 2 2-trifluoroacetone